JP6503613B2 - Powder container - Google Patents

Description

  The present invention relates to a powder container. More particularly, it relates to a powder container for supplying powder to a powder molding apparatus.

  Powder metallurgy is a technology for producing machine parts having relatively complicated shapes. In this method, powders of various compositions including an iron-based material are pressure-formed into a desired shape, and the obtained compact (green compact) is heated and sintered. And, in the powder forming apparatus which produces the above-mentioned compact using a die, it passes through the hose etc. from the powder container which accommodates the powder of the raw material in the shoe box which slides on the die plate and fills the powder into the die. The powder is then supplied.

  In the powder container, usually about 1000 kg of powder is accommodated. The powder is adjusted to a desired composition using a mixer in a compounding ridge separate from the building where the pressure forming is performed. And the obtained powder is filled in the inside of the powder container arrange | positioned under the said powder scattering prevention hood via the powder scattering prevention hood arrange | positioned under the discharge port of the said mixer. The powder container filled with powder is carried by a forklift or the like to a predetermined position in a building where the powder forming apparatus is installed.

  In order to obtain a sintered body with the strength and characteristics as specified, it is necessary to supply a homogeneous powder into the shoe box of the powder forming apparatus. Therefore, it is desirable that the behavior of the powder when supplied from the powder container to the shoe box is a so-called mass flow in which the material previously charged into the powder container is discharged first, but carbon is one of the powder compositions. In some cases, auxiliary materials such as lubricants (wax etc.) adhere to and deposit on the wall of the powder container, resulting in so-called funnel flow which is discharged last despite being previously introduced. When funnel flow occurs, carbon segregation may occur, and the bulk density of the powder may vary. As a result, there is a problem that the strength and characteristics of the obtained product vary and the yield is lowered.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a powder container capable of mass flow of powder behavior by preventing or suppressing adhesion or deposition of powder on a wall surface. And

A powder container according to an aspect of the present invention is a powder container for supplying a powder containing an iron-based material as a main raw material to a powder forming apparatus,
A cylindrical body having a powder inlet at its upper end,
A conical inclined portion connected to the lower end opening of the main body portion and having a powder discharge port at the lower end;
The surface roughness Rz (μm) of the inner wall surface of the inclined portion is 3 or less ,
The inclination angle of the inner wall surface of the inclined portion Ri 50 to 80 ° der, and
The powder contains at least carbon as an auxiliary material .
In the present specification, the “surface roughness Rz” is the surface roughness (μm) defined in JIS B 0659-1 (2002).

  According to the above-mentioned invention, it is possible to make the behavior of the powder a mass flow by preventing or suppressing adhesion and deposition of the powder on the wall surface.

BRIEF DESCRIPTION OF THE DRAWINGS It is cross-sectional explanatory drawing of the powder filling apparatus containing one Embodiment of the powder container of this invention.

Description of the embodiment of the present invention
First, the embodiments of the present invention will be listed and described.
A powder container according to one aspect of the present invention is
(1) A powder container for supplying a powder consisting mainly of an iron-based material to a powder forming apparatus,
A cylindrical body having a powder inlet at its upper end,
A conical inclined portion connected to the lower end opening of the main body portion and having a powder discharge port at the lower end;
The surface roughness Rz of the inner wall surface of the inclined portion is 3 or less, and
The inclination angle of the wall surface of the inclined portion with respect to the horizontal plane is 50 to 80 °.

  In the powder container according to this aspect, since the surface roughness Rz of the inner wall surface of the inclined portion is 3 or less, the friction between the powder supplied into the powder container and the inner wall surface can be reduced. Flow can be improved. Moreover, since the inclination angle with respect to the horizontal surface of the wall surface of an inclination part is 50-80 degrees, the flow of the powder which goes to a powder discharge port can be improved. By using such surface roughness and inclination angle, the behavior of the powder when supplied from the powder container to the shoe box can be mass flow, and the powder adheres to and is deposited on the inner wall surface of the inclined portion, It is possible to prevent the behavior of the powder from becoming funnel flow. As a result, segregation of carbon contained in the powder as an auxiliary material and fluctuation of bulk density of the powder can be prevented or suppressed, and as a result, the strength and characteristics of the obtained product can be stabilized and yield can be improved. it can.

(2) In the powder container of the above (1), the powder may contain at least carbon as an auxiliary material. In this case, segregation of carbon can be prevented or suppressed, and as a result, the strength and characteristics of the obtained product can be stabilized, and the yield can be improved.

(3) In the powder container of said (1) or (2), it is preferable that surface roughness Rz of the inner wall face of the said inclination part is 1.6-3.0. In this case, the friction between the powder supplied into the powder container and the inner wall can be further reduced, and the flow of the powder can be further improved.

(4) In the powder container of said (1)-(3), it is preferable that the inclination angle of the wall surface of the said inclination part is 56-75 degrees. In this case, the flow of powder towards the powder outlet can be further improved.

Details of the Embodiment of the Present Invention
Hereinafter, an embodiment of a powder container of the present invention will be described in detail with reference to the attached drawings. The present invention is not limited to these exemplifications, but is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

  FIG. 1 is a cross-sectional explanatory view of a powder filling device P including a powder container 1 according to an embodiment of the present invention. The powder filling device P is a device for preparing a powder used in the powder forming device and filling the powder container 1, and includes a mixer 2, a powder scattering prevention hood 3, and the powder container 1.

  The powder container 1 accommodates powder supplied to a pressure forming apparatus for producing a formed body (compacted body). The powder is composed of an iron-based material which is a main material and an auxiliary material such as carbon and a lubricant (wax etc.), and these materials are adjusted to a predetermined composition by the mixer 2.

  The powder adjusted to the predetermined composition is prevented from being shattered from the outlet 2a of the mixer 2 installed on the stage S, via the shatterproof hood 3 arranged below the mixer 2 It is supplied into the powder container 1 disposed below the hood 3. A duct 4 is connected to the powder scattering prevention hood 3, and by suctioning air in the powder scattering prevention hood 3 using the duct 4, the inside of the powder scattering prevention hood 3 is under negative pressure. Accordingly, it is possible to suppress or prevent the deterioration of the working environment in the compounding ridge, in which the powder soaring at the time of discharge from the mixer 2 leaks from the upper opening 3a or the lower opening 3b of the powder scattering prevention hood 3 to the outside.

  The powder container 1 which concerns on this embodiment is equipped with the main-body part 5 and the inclination part 6, and is arrange | positioned on the mount-frame B made from steel. The main body portion 5 has a cylindrical shape, has a powder receiving port 5a at its upper end, and has an opening at its lower end. The inclined portion 6 has a conical shape in which the diameter decreases toward the lower side, and the opening on the larger diameter side is connected to the opening at the lower end of the main body portion 5. At the lower end of the inclined portion 6, a cylindrical powder outlet 7 for supplying the powder to the powder molding device is formed. A flange 8 is provided at the lower end of the powder discharge port 7, and the flange 9 of the discharge valve 10 having a flange 9 provided at one end is connected to the flange 8. The discharge valve 10 in the present embodiment is a motorized butterfly valve. When discharging the powder, the discharge valve 10 is opened and the powder in the powder container 1 is supplied to the shoe box of the powder forming apparatus. The material of the powder container 1 is not particularly limited in the present invention, but can be made of, for example, stainless steel.

  The surface roughness Rz of the inner wall surface 6a of the inclined portion 6 of the powder container 1 is processed to be 3 or less, preferably 1.6 to 3.0. As a processing method for achieving such surface roughness Rz, for example, buffing can be exemplified, but it is not particularly limited in the present invention as long as the surface roughness Rz is 3 or less. When the surface roughness Rz of the inner wall surface 6a exceeds 3, it relates to the inclination angle of the wall surface of the inclined portion 6 described later, but the powder supplied into the powder container 1 adheres to the inner wall surface 6a of the inclined portion 6, there's a possibility that. In particular, when carbon is contained as an auxiliary material, such carbon has an average size of 20 to 30 μm, which is smaller than 60 μm of iron powder which is a main raw material, and has a scale-like shape, The friction with the inner wall surface 6a is increased, and there is a possibility that the inner wall surface 6a may be attached or accumulated. As a result, the behavior of the powder when supplied to the powder forming apparatus becomes funnel flow, and there is a possibility that the segregation of carbon and the fluctuation of density of the carbon may occur.

  The inclination angle θ of the wall surface of the inclined portion 6 with respect to the horizontal plane is set to 50 to 80 °, preferably 56 to 75 °. If the inclination angle θ is smaller than 50 °, it is also related to the surface roughness Rz of the inner wall surface 6a described above, but the flow of the powder supplied into the powder container 1 at the inclined portion 6 becomes worse and causes funnel flow. It becomes.

  On the other hand, in the present embodiment, since the surface roughness Rz of the inner wall surface 6a of the inclined portion 6 is 3 or less, the friction between the powder supplied into the powder container 1 and the inner wall surface 6a is reduced. And the flow of powder can be improved. Moreover, since the inclination angle with respect to the horizontal surface of the wall surface of the inclination part 6 is 50-80 degrees, the flow of the powder which goes to the powder discharge port 7 can be improved. By using such surface roughness and inclination angle, the behavior of the powder when supplied from the powder container 1 to the shoe box can be mass flow, and the powder adheres to the inner wall surface 6 a of the inclined portion 6 and deposits. Thus, the behavior of the powder can be prevented from becoming funnel flow. When the inclination angle is larger than the upper limit (80 °), the powder container 1 becomes long and it becomes difficult to handle.

[Other Modifications]
The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims.
For example, in the embodiment described above, the height (the size in the vertical direction at the time of use) of the main body of the powder container is made lower than the height of the inclined portion, but both heights depend It can be suitably changed accordingly.
Moreover, in the embodiment described above, the discharge valve including a butterfly valve is used as a mechanism for discharging the powder, but other configurations such as a slide valve may be used.

1: powder container 2: mixer 3: powder scattering prevention hood 3 a: upper opening 3 b: lower opening 4: duct 5: main body 6: inclined portion 6 a: inner wall surface 7: powder outlet 8: flange 9: flange 10: 10 Discharge valve B: Mounting frame P: Powder filling device S: Stage

Claims (3)

A powder container for supplying a powder containing iron-based material as a main raw material to a powder forming apparatus,
A cylindrical body having a powder inlet at its upper end,
A conical inclined portion connected to the lower end opening of the main body portion and having a powder discharge port at the lower end;
The surface roughness Rz (μm) of the inner wall surface of the inclined portion is 3 or less ,
The inclination angle of the inner wall surface of the inclined portion Ri 50 to 80 ° der, and
A powder container, wherein the powder contains at least carbon as an auxiliary material . The powder container according to claim 1, wherein a surface roughness Rz (μm) of an inner wall surface of the inclined portion is 1.6 to 3.0. The inclination angle of the inner wall surface of the inclined portion is 56-75 °, the powder container according to claim 1 or claim 2.

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